That's what bothers me about this. If drilling with microwaves works, why aren't there industrial applications? Laser cutters are widely used, from little ones that engrave plastic to big ones that cut steel plate. Yet nobody seems to be selling microwave cutters. In industrial applications, you don't even have to fit the microwave generator into the hole and keep it working in a hostile environment.
The idea was suggested back in 2002, but seems to have gone nowhere.
[1] https://www.researchgate.net/publication/11075717_The_Microw...
This wants to dump a lot of heat into a large area, and there’s industrial uses for that: https://industrialmicrowave.com/industrial-microwave-heating...
You also have a device at home that uses microwaves for heating larger volumes of material…
Geothermal power is indeed cool, but to get it usable anywhere on Earth instead of a few places where magma currents happen to be near the surface, we'll probably need several orders of magnitude deeper and wider holes than we're currently capable of drilling just for starters. Can these guys do the job? Maybe, but let's just say I'm not planning to invest in them.
[0] https://www.quaise.energy/news/from-lab-to-field-testing